Articulating suturing device and method

ABSTRACT

Devices, systems, and methods for suturing of body lumens allow the suturing of vascular puncture sites located at the distal end of a percutaneous tissue tract. An elongated articulated foot near a distal end of a shaft is inserted through the penetration and actuated so that the foot extends along the lumenal axis. The foot carries suturing attachment cuffs, and needles are advanced from the shaft through the vessel wall outside of the penetration and into engagement with the needle cuffs after the foot has been drawn proximally up against the endothelial surface of the blood vessel. The cross-section of the shaft within the tissue tract can be minimized by laterally deflecting the needles as they leave the shaft, while tapered depressions within the foot can guide the advancing needles into engagement with the cuffs. The cuffs lockingly engage the needles and can be withdrawn proximally along the needle paths and through the tissue tract so as to form a loop of suture across the puncture. The articulating foot may be realigned with the shaft and withdrawn proximally through the tissue tract without dilating the tissue tract.

BACKGROUND OF THE INVENTION

This application is a division of, and claims the benefit of priorityfrom application no. 09/262,402, filed on Mar. 4, 1999, the fulldisclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to apparatus and methods for thesuturing of body lumens. More particularly, the present inventionrelates to techniques for percutaneous closure of arterial and venouspuncture sites, which are usually accessed through a tissue tract.

A number of diagnostic and interventional vascular procedures are nowperformed translumenally. A catheter is introduced to the vascularsystem at a convenient access location and guided through the vascularsystem to a target location using established techniques. Suchprocedures require vascular access, which is usually established duringthe well-known Seldinger technique, as described, for example, inWilliam Grossman's “Cardiac Catheterization and Angioplasty,” 3 ^(rd)Ed., Lea and Febiger, Philadelphia, 1986, incorporated herein byreference. Vascular access is generally provided through an introducersheath, which is positioned to extend from outside the patient body intothe vascular lumen.

When vascular access is no longer required, the introducer sheath isremoved and bleeding at the puncture site stopped. One common approachfor providing hemostasis (the cessation of bleeding) is to applyexternal force near and upstream from the puncture site, typically bymanual or “digital” compression. This approach suffers from a number ofdisadvantages. It is time consuming, frequently requiring one-half houror more of compression before hemostasis is assured. Additionally, suchcompression techniques rely on clot formation, which can be delayeduntil anticoagulants used in vascular therapy procedures (such as forheart attacks, stent deployment, non-optical PTCA results, and the like)wear off. This can take two to four hours, thereby increasing the timerequired before completion of the compression technique. The compressionprocedure is further uncomfortable for the patient and frequentlyrequires analgesics to be tolerable. Moreover, the application ofexcessive pressure can at times totally occlude the underlying bloodvessel, resulting in ischemia and/or thrombosis. Following manualcompression, the patient typically remains recumbent from four to asmuch as twelve hours or more under close observation so as to assurecontinued hemostasis. During this time renewed bleeding may occur,resulting in blood loss through the tract, hematoma and/orpseudo-aneurysm formation, as well as arteriovenous fistula formation.These complications may require blood transfusion and/or surgicalintervention.

The incidence of complications from compression induced hemostasisincreases when the size of the introducer sheath grows larger, and/orwhen the patient is anti-coagulated. It is clear that the compressiontechnique for arterial closure can be risky, and is expensive andonerous to the patient. Although the risk of complications can bereduced by using highly trained individuals, dedicating such personnelto this task is both expensive and inefficient. Nonetheless, as thenumber and efficacy of translumenally performed diagnostic andinterventional vascular procedures increases, the number of patientsrequiring effective hemostasis for a vascular puncture continues toincrease.

To overcome the problems associated with manual compression, the use ofbioabsorbable fasteners or sealing bodies to stop bleeding haspreviously been proposed. Generally, these approaches rely on theplacement of a thrombogenic and bioabsorbable material, such ascollagen, at the superficial arterial wall over the puncture site. Whilepotentially effective, this approach suffers from a number of problems.It can be difficult to properly locate the interface of the overlyingtissue and the adventitial surface of the blood vessel. Locating thefastener too far from that interface can result in failure to providehemostasis, and subsequent hematoma and/or pseudo-aneurysm formation.Conversely, if the sealing body intrudes into the artificial lumen,intravascular clots and/or collagen pieces with thrombus attached canform and embolize downstream, causing vascular occlusion. Also, thrombusformation on the surface of a sealing body protruding into the lumen cancause a stenosis, which can obstruct normal blood flow. Other possiblecomplications include infection, as well as adverse reaction to thecollagen or other implant.

A more effective approach for vascular closure has been proposed in U.S.Pat. Nos. 5,417,699, 5,613,974; and PCT published Patent Application No.PCT/US96/10271 filed on Jun. 12, 1996, the full disclosures of which areincorporated herein by reference. A suture applying device is introducedthrough the tissue tract with a distal end of the device extendingthrough the vascular puncture. One or more needles in the device arethen used to draw suture through the blood vessel wall on opposite sidesof the puncture, and the suture is secured directly over the adventitialsurface of the blood vessel wall to provide highly reliable closure.

While a significant improvement over the use of manual pressure, clamps,and collagen plugs, certain design criteria have been found to beimportant to successful suturing to achieve vascular closure. Forexample, it is highly beneficial to properly direct the needles throughthe blood vessel wall at a significant distance from the puncture sothat the suture is well anchored in the tissue and can provide tightclosure. It is also highly beneficial to insure that the needledeployment takes place when the device is properly positioned relativeto the vessel wall. The ease of deployment and efficacy of the procedurecan further be enhanced by reducing the cross-section of that portion ofthe device which is inserted into the tissue tract and/or the vesselitself, which may also allow closure of the vessel in a relatively shortamount of time without imposing excessive injury to the tissue tract orvessel.

For the above reasons, it would be desirable to provide improveddevices, systems, and methods for suturing vascular punctures. It wouldbe particularly beneficial if these improved devices provided some orall of the benefits while overcoming one or more of the disadvantagesdiscussed above.

DESCRIPTION OF THE BACKGROUND ART

U.S. Pat. Nos. 5,700,273, 5,836,956, and 5,846,253 describe a woundclosure apparatus and method in which needles are threaded with sutureinside a blood vessel. U.S. Pat. No. 5,496,332 describes a wound closureapparatus and method for its use, while U.S. Pat. No. 5,364,408describes an endoscopic suture system.

U.S. Pat. No. 5,374,275 describes a surgical suturing device and methodof use, while U.S. Pat. No. 5,417,699 describes a device and method forthe percutaneous suturing of a vascular puncture site. An instrument forclosing trocar puncture wounds is described in U.S. Pat. No. 5,470,338,and a related device is described in U.S. Pat. No. 5,527,321. U.S. Pat.No. 5,507,757 also describes a method of closing puncture wounds.

SUMMARY OF THE INVENTION

The present invention provides improved devices, systems, and methodsfor suturing of body lumens. The device often allows the suturing ofvascular puncture sites located at the distal end of a percutaneoustissue tract with greater ease, in less time, and with less patienttrauma than known systems. These improvements are generally providedthrough the use of shafts having smaller cross-sections than priorsuturing systems. In the exemplary embodiment, an elongate articulatedfoot near a distal end of a shaft is inserted through the penetrationand actuated so that the foot extends along the lumenal axis. The footcarries suture attachment cuffs, and can be drawn proximally up againstthe endothelial surface of the blood vessel. Needles are advanced fromthe shaft, through the vessel wall beyond the penetration, and intoengagement with the needle cuffs. The cross-section of the shaft withinthe tissue tract can be minimized by laterally deflecting the needlesbefore they leave the shaft, while tapered depressions within the footcan help guide the advancing needles into engagement with the cuffs. Thecuffs lockingly engage the needles so that the cuffs can be withdrawnproximally along the needle paths through the tissue tract so as to forma loop of suture across the puncture without having to thread theneedles directly with the suture inside the blood vessel. The sutureloop may be drawn distally from the shaft, proximally from within theblood vessel, or laterally down one of the needle paths, across thepuncture, and out the opposing path. Regardless, the articulating footmay be realigned with the shaft and withdrawn proximally through thetissue tract in a small profile configuration. The use of anarticulatable foot in combination with lateral deflection of the needlescan avoid dilation of the tissue tract, as was often necessary usingknown puncture closure systems.

In a first aspect, the invention provides a method for suturing apuncture through a vessel wall of a blood vessel. The puncture isdisposed within a tissue tract of a patient body, and the methodcomprises attaching a flexible filament to a first fitting. The firstfitting is inserted through the tissue tract and positioned adjacent thevessel wall, and a needle path is formed by advancing a first needlethrough the vessel wall. The needle is coupled with the first fitting,and the first needle, the first fitting, and at least a portion of thefilament are withdrawn through the vessel wall along the needle path.

First and second fittings will often be coupled to the flexiblefilament, and will generally be positioned so that the puncture isdisposed therebetween. The flexible filament will often comprise asuture extending between the first and second fittings, with eachfitting being drawn proximally by an associated needle so as to form thesuture loop. Alternatively, at least one of the needles may include adetachable tip and may advance a suture distally along the needle pathas the needle penetrates through the vessel wall. The flexible filamentcan again couple the first and second fittings, here allowing bothfittings to be withdrawn along a single needle path so that the sutureadvances down along the first needle path, laterally across thepuncture, and then out the other needle path.

Positioning of the fittings is generally effected by articulating anelongate foot within the blood vessel so that the foot extends along thevessel axis. A confirmation lumen may extend along a shaft supportingthe foot to ensure that the foot is positioned within the vessel priorto articulation. Once the foot is properly articulated, it can bewithdrawn to firmly engage the endothelial layer of the vessel. The footwill preferably include tapering depressions which direct the advancingneedle toward the fitting, and the suture or other flexible filamentadjacent the fittings will often be releasably restrained within anarrow slot extending from the depression. The suture or other flexiblefilament and its associated slot will preferably be arranged to avoidentanglement of the advancing needle in the suture, and to ensure thatthe fitting and suture can be withdrawn proximally as the needle isretracted. An atraumatic, flexible monorail guidebody may extend fromthe shaft and/or the articulatable foot to facilitate alignment of thefoot with the vessel, and also to help provide hemostasis while the knotis tied. A wide variety of foot articulation mechanisms may be provided,with deployment preferably being effected when the foot is disposedentirely within the vessel and using an actuator and foot motion thatavoid dilation of the puncture.

In another aspect, the invention provides a method for suturing anopening in a tissue. The method comprises inserting a distal end of aprobe through the opening, the probe defining a probe axis. An elongatedfoot of the probe is articulated so that first and second ends of thefoot extend laterally with the opening aligned therebetween. A firstneedle path is formed from the probe, through the tissue, and to thefirst end of the foot. A second needle path is formed from the probe,through the tissue, and to the second end of the foot. Suture isadvanced along the first and second needle paths to position a sutureloop across the opening.

In another aspect, the invention provides a method for suturing a bloodvessel. The vessel has a vessel wall, and the method comprises advancinga shaft toward the vessel wall. The shaft has an axis and a plurality ofneedle guides. A foot is deployed adjacent the vessel wall so that thefoot extends laterally from the shaft. A plurality of needles areadvanced from the needle guides of the shaft to the foot to form needlepaths through the vessel wall. The needle guides deflect the needleslaterally so that a needle path width between the needles is greaterthan a cross-sectional dimension of the shaft. Suture is advanced alongthe needle paths to position at least one suture loop across thepuncture.

In yet another method of the present invention, a blood vessel issutured through a tissue tract of a patient body. The vessel has avessel wall, and the method comprises inserting a distal end of a probethrough the puncture and into the blood vessel. A first end of thesuture is advanced from the probe within the tissue tract, through thevessel wall, and into the vessel. The first end of the suture iswithdrawn from the vessel through the vessel wall, and through a bightof the suture to form a loop of suture across the puncture. The firstend of the suture and a second end of the suture adjacent the bight aretensioned to detach the bight from the probe and form a knot affixingthe loop of suture across the puncture. Advantageously, the bight ofsuture may be pre-tied before the probe is inserted into the tissuetract, the bight optionally being releasably attached to the probe.

In a device aspect, the invention provides a system for suturing a bloodvessel. The vessel has a vessel wall, and the system comprises a needlehaving a proximal end and a distal end suitable for forming a needlepath through the vessel wall. The needle has a recessed engagementsurface adjacent the distal end. The system further comprises a flexiblefilament and a fitting attached to the filament. The fitting has anopening and a tab extending into the opening, the tab securinglyengaging the engagement surface when the needle advances through thevessel wall and into the opening, so that the fitting and at least aportion of the filament can be withdrawn proximally along the needlepath by the needle.

In a further device aspect, the invention provides a system for suturinga puncture of a blood vessel within a tissue tract. The vessel has avessel wall and defines an axis, and the system comprises a shaft havinga proximal handle and a distal end suitable for insertion along thetissue tract and into the vessel through the puncture. A foot is mountednear the distal end of the shaft. The foot has plurality of needlereceptacles extendable laterally from the shaft. A flexible filamentextends between the receptacles of the foot. A plurality of needles areadvanceable distally and laterally from the shaft, through the vesselwall outside the puncture, and to the receptacles of the foot.

In yet another device aspect, the invention provides a system forsuturing a puncture of a blood vessel within a tissue tract. The vesselhas a vessel wall, and the system comprises a shaft having a proximalhandle and a distal end suitable for insertion along the tissue tractand into the vessel through the puncture. A foot is mounted near thedistal end of the shaft. The foot has a first needle receptacle and isarticulatable from a small profile configuration to a large profileconfiguration by actuation of the handle. A first fitting is removablymounted adjacent the first needle receptacle. A filament is coupled tothe first fitting. A first needle is advanceable from the shaft to thefirst needle receptacle on the articulated foot. The first fittingsecurely engages the first needle so that the secured first fitting andat least a portion of the filament can be drawn through the vessel wallby the first needle.

In a still further device aspect, the invention provides a probe forsuturing an opening in a tissue. The probe comprises a shaft having aproximal end and a distal end and defining an axis therebetween. Theshaft has a size and configuration suitable for insertion through theopening in the tissue. An elongate foot is movably mounted to the shaft.An actuator extends along the shaft distally to the foot. Movement ofthe actuator slides the foot axially and pivots the foot from a lowprofile configuration to a deployed configuration extending laterallyfrom the shaft. A suture is supported by the foot, and a needle isadvanceable from the shaft, through the tissue, and to the deployedfoot.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of a percutaneous blood vessel closure deviceaccording the principles of the present invention.

FIG. 2 illustrates the vessel closure device of FIG. 1 in which anelongate foot is shown in a deployed position.

FIGS. 2A-C illustrate actuation of a foot and advancement of needlesfrom a shaft to the articulated foot in a probe similar to the probe ofFIG. 1.

FIG. 3A is a detailed view showing the foot of the vessel closure deviceof FIG. 1 in a parked position prior to deployment.

FIG. 3B is a detailed view showing the foot of the vessel closure deviceof FIG. 1 in a deployed position.

FIGS. 4 and 4A are perspective views illustrating a suture attachmentcuff and an associated barbed needle for use in the vessel closuredevice of FIG. 1.

FIG. 5 is a cross-sectional view showing the barbed needles securinglyengaging the suture cuffs of the deployed foot.

FIGS. 6A-C illustrate one embodiment of a deployable foot, in which thefoot slides and pivots when drawn proximally by a tension member.

FIG. 7 illustrates the suture cuff positioned within a needlereceptacle, and also shows how the suture is releasably secured within aslot extending radially from the needle receptacle.

FIGS. 8A-C illustrate an alternative foot articulation mechanism inwhich lateral slots on the foot receive pins from the shaft to allow thefoot to pivot and slide axially.

FIGS. 9A and B illustrate a still further alternative foot actuationmechanism in which the foot slides axially within a slot.

FIGS. 9C and D illustrate a further foot actuation mechanism in whichrelative movement between the sides of a two-part shaft actuates thefoot.

FIGS. 10A-D illustrate alternative structures and techniques foravoiding entanglement of the needle with the suture.

FIGS. 11A-E illustrate an alternative closure system and method for itsuse in which a first needle advances the suture to the foot, while asecond needle engages and withdraws both the first and second suturecuffs, a flexible filament connecting the suture cuffs, and at least aportion of the suture from within the blood vessel so as to complete apre-tied knot.

FIGS. 12A and B illustrate an alternative probe having two pairs ofneedles and a foot with four needle receptacles so as to form two loopsof suture across a puncture of a blood vessel.

FIGS. 13A-G illustrate a method for use of a suture system so as toeffect hemostasis of a blood vessel puncture through a tissue tract.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

Referring now to FIG. 1, a vessel closure device 10 generally has ashaft 12 having a proximal end 14 and a distal end 16. A proximalhousing 18 supports a needle actuation handle 20. A flexible, atraumaticmonorail guidebody 22 extends distally of distal end 16 of shaft 12.

As can be seen with reference to FIG. 2, a foot 24 is articulatablymounted near the distal end of shaft 12. Foot 24 moves between a lowprofile configuration, in which the foot is substantially aligned alongan axis of shaft 12 (as illustrated in FIG. 1), to a deployed position,in which the foot extends laterally from the shaft, upon actuation of afoot actuation handle 26 disposed on proximal housing 18.

FIGS. 2A through C illustrate the structure and actuation of foot 24 ofa preferred probe 10′ having a modified proximal housing, and also showhow needles 38 can be advanced distally from shaft 12 to the foot bydepressing needle actuation handle 20.

Actuation of foot 24 is illustrated more clearly in FIGS. 3A and B. Inthe parked position illustrated in FIG. 3A, foot 24 extendssubstantially along axis 28 of shaft 12. Note that the axis of the shaftneed not be straight, as the shaft may curve somewhat, particularlyadjacent the foot. In the exemplary embodiment, foot 24 is substantiallydisposed within a foot receptacle 30 of shaft 12 so as to minimize thecross-section of the device adjacent the foot prior to deployment.Advantageously, prior to deployment of the foot, device 10 can have across-section adjacent foot 24 of about 7 Fr or less, ideally having across-section of about 6 Fr or less for the entire device distally ofthe proximal end 14 of shaft 12.

Actuation of foot handle 26 slides a foot actuation wire 32 proximally,pulling foot 24 from a parked position to the deployed positionillustrated in FIG. 3B. Once deployed, a first end 24 a and a second end24 b of foot 24 extend laterally from the shaft. Suture 34 herecomprises a continuous filament with ends disposed in needle receptaclesadjacent each end of the foot. An intermediate portion of suture 34 mayextend proximally along a suture lumen of shaft 12 to and/or beyondproximal housing 18. Alternatively, in preferred probe 10′, the lengthof suture between the ends may extend distally within flexible guidebody22, preferably in a dedicated lumen (separate from the monorailguidewire lumen). In still further alternatives described below, a shortlength of suture or some other flexible filament may extendsubstantially directly between the needle receptacles.

Shaft 12 also includes a foot position verification lumen that extendsdistally from a position verification port 36 to a position indicator athousing 18. When the foot is properly positioned within the bloodvessel, blood pressure will cause blood to flow proximally through theindicator lumen to the indicator. The indicator may optionally comprisea blood exit port, a clear receptacle in which blood is visible, or thelike. In the exemplary embodiment, the indicator of handle 18 comprisesa length of clear tubing extending from housing 18 (not shown) in whichthe blood is clearly visible. It should be understood that a widevariety of alternative position verifications sensors might be used,including electrical pressure sensors, electrolytic fluid detectors, orthe like.

The structures used in positioning a loop of suture across the puncturecan be understood with reference to FIGS. 4, 4A, and 5. In generalterms, needles 38 extend from shaft 12 into secured engagement withfittings 40 attached to sutures 34. More specifically, needles 38include a barbed end 42 defining a recessed engagement surface 44.Fittings 40 are roughly cylindrical structures having an axial channel46 which receives barbed end 44 of needle 38 therein. A first slot iscut in fitting 44 so as to define at least one tab 48. Tabs 48 can beresiliently biased inward into channel 46. As needle 38 advances intofitting 40, barbed end 42 resiliently displaces tab 48 clear of channel46 so as to allow the barbed end to pass axially into the fitting. Oncebarbed end 42 is disposed axially beyond tab 48, the tab resilientlyflexes back into the channel, capturing needle 38 by engagement betweenthe tab and recessed surface 44. As each tab can hold the fitting inplace on the needle, the use of more than one tab increases thereliability of the system. Ideally, three tabs are provided, asillustrated in FIG. 4A.

To facilitate attachment of fitting 40 to suture 34, a second slot cutin the tubular fitting structure defines a suture attachment collar 50.Optionally, collar 50 may be crimped about suture 34 to mechanicallyaffix the suture to fitting 40. In addition and/or instead of mechanicalcrimping, suture 34 may be bonded to fitting 40 using an adhesive, heat,fasteners, knots, or the like.

Fitting 40 is quite small in size, and is generally configured tofacilitate withdrawing the fitting (and the attached suture) along withneedle 38 axially through the vessel wall along the needle path. Needle38 will generally have a cross-sectional width of between about 0.010inches and 0.020 inches. Barb 42 will extend laterally so as to definean engagement surface 44 having a protruding length of between about0.002 inches and 0.005 inches. Fitting 40 will preferably have across-sectional size roughly corresponding to or only slightly largerthan needle 38. Fitting 40 will typically have an outer lateral width ofbetween about 0.014 inches and 0.025 inches, and an axial length ofbetween about 0.035 inches and 0.050 inches. Channel 46 will be sized toreceive at least a portion of needle 38, and will generally have a widthof between about 0.010 inches and 0.020 inches. Suture 34 willpreferably extend axially opposite the open end of channel 46 so as tominimize drag when the suture is drawn proximally along the needle path.In the exemplary embodiment, needle 38 has a diameter of about 0.020inches, while the fitting comprises a tube having an outer diameter ofabout 0.020 inches, an inner diameter of about 0.016 inches, and anoverall length of about 0.047 inches. The fitting will typicallycomprise a resilient material, preferably comprising a metal, and in theexemplary embodiment, comprising stainless steel.

Needles 38 typically have a length of between about 5.0 inches and 6.0inches, and will preferably be sufficiently stiff to be advanced incompression through the vessel wall (and adjacent tissues) for up to 0.5inches when supported in cantilever. Nonetheless, the needles willideally be flexible enough to be laterally deflected within shaft 12, ascan be understood with reference to FIG. 5. Needles 38 generallycomprise a high strength metal, ideally comprising stainless steel.Fittings 40 will also preferably comprise a flexible material to allowtab 48 to flex out of the way of barbed end 42, and to resilientlyrebound and engage recessed surface 44. In the exemplary embodiment,barbed end 42 has a diameter of about 0.015 inches, with the diameter ofthe needle decreasing to about 0.008 inches proximally of the barb so asto define the recessed engagement surface.

As was generally described above, foot 24 includes needle receptacles 52adjacent the ends of the foot. A fitting 40 (with an associated end ofsuture 34) is disposed within each needle receptacle, and a surface ofthe receptacle tapers proximally and outwardly so as to guide theadvancing needles 38 into engagement with fittings 40 when foot 24 is inthe deployed position. As fittings 40 (and associated portions of suture34) are releasable supported in the foot, needles 38 can be withdrawnproximally so as to draw the fittings and suture ends from the footproximally into (and optionally through) shaft 12. The needlereceptacles of the exemplary embodiment taper outward at an anglebetween 20 and 35 degrees from the centerline of fitting 40, and thefitting is held in a recess having a diameter of about 0.0230 inches anda length of about 0.042 inches. A lateral opening or window through theside of foot to the fitting recess may be provided to facilitate needleand/or cuff positioning during assembly of the probe, and a protrudingcollar near the proximal end of the fitting recess may help keep thefitting in position.

FIG. 5 also illustrates the lateral deflection of needles 38 by needleguides 54 of shaft 12. This lateral deflection of the needles allows theuse of a small diameter shaft, while still encompassing sufficienttissue within the suture loop on opposite sides of the puncture so as toeffect hemostasis when the suture looped is tightened and secured. Inthe exemplary embodiment, shaft 12 comprises an outer casing of abiocompatible material such as stainless steel, carbon fiber, nylon,another suitable polymer, or the like. Needle guides 54 may be definedat least in part as lumens formed within the casing of a polymericmaterial such as nylon or the like. In some embodiments, shaft 12 maycomprise a carbon fiber filled nylon, or carbon fiber filled with analternative material.

One example of a suitable structure and articulation motion for foot 24is illustrated in FIGS. 6A and B. Foot actuation wire 32 (see FIG. 3A)rides in a lumen of shaft 12, and draws foot 24 from a parked position(shown in FIG. 6A) to a deployed position (shown in FIG. 6B) through acombination of sliding and pivoting of the foot. The foot remainssupported throughout its range of motion by arms disposed laterally oneither side of the foot, the arms defining (at least in part) footreceptacle 30. Once foot 24 is deployed, needle receptacles 52 and/orthe fittings disposed therein will preferably define a lateral suturingwidth 56 in a range from about 0.260 inches to about 0.300 inches. Foot24 may be machined or cast from a polymer or metal, but will preferablycomprise a polymer such as carbon fiber filled nylon. In some cases,foot 24 may be molded as two separate halves which can subsequently beaffixed together. Needles 38 advance from the fixed needle guides 54,and are laterally directed into fittings 40 by receptacles 52, asillustrated in FIG. 6C. In general, a shape memory alloy such asNitinol™ in its superelastic regime provides a particularly advantageousactuator wire for manipulating foot 24.

Referring now to FIG. 7, fittings 40 and suture 34 will be withdrawnproximally by the needles from needle receptacles 52. To releasablysupport fittings 40 and suture 34 and avoid entanglement of the suturein the needles, suture 34 is fittingly received within a slot 58 whichextends laterally from needle receptacles 52. As the needles pull thefitting axially from needle receptacles 52, suture 34 is pulled fromslot 58 and free from foot 24. Bending of the suture proximally withinthe suture slot can also locally increase the suture width, so that theinteraction between the bent suture and the slot can help hold thefitting in the recess.

A wide variety of foot actuation mechanisms might be used within thescope of the present invention. A first alternative foot actuationarrangement is illustrated in FIGS. 8A-C. In this embodiment, a shaft 12i has pins 60 which ride in associated slots 62 of a foot 24 i. Proximalmotion of an actuation wire causes foot 24 i to move axially androtationally, with pins 60 sliding along slot 62, and the foot pivotingabout the pins. In this embodiment, guidebody 22 extends directly fromthe foot, as illustrated in FIG. 8C.

A still further alternative foot actuation mechanism is illustrated inFIGS. 9A and B. In this embodiment, slidable foot 24 ii is slidinglyreceived within a receptacle 30 of shaft 12 ii. Sliding of the foot 24ii from the parked position of FIG. 9A to the deployed position of FIG.9B places the needle receptacles 52 in the paths of needles from theshaft 12 ii without pivoting of the foot. Guidebody 22 (see FIG. 1) willextend here from a distal end of shaft 12 ii at a fixed angle from theshaft. Optionally, insertion through the tissue tract may be facilitatedby including an additional bend in the shaft axis adjacent the guidebodyon many embodiments.

Yet another foot actuation mechanism can be understood with reference toFIGS. 9C and D. Shaft 12 iii is formed in two parts, which slide axiallyrelative to each other when foot actuation lever 26 iii moves, using anoffset crank arrangement. A similar offset crank supports foot 24 iii,so that the sliding shaft parts cause the foot to pivot as shown.

A variety of features may be included in the articulatable foot, theneedle receptacle, and/or the needle to avoid tangling of the needle inthe suture as the needle is directed to the fitting. As illustrated inFIG. 10A, a moveable flap 64 may extend over slot 58 so that theadvancing needle slides along the flap toward the fitting, rather thanentering the slot and engaging the suture directly. Flap 64 may beaffixed along one side of the slot, with the other side of the flapflexing into the receptacle to release the suture from slot 58 when thefitting and suture are withdrawn by the needle.

An alternative mechanism for avoiding entanglement of the needle withthe suture is illustrated 10B. In this embodiment, needle receptacles 52i have tangential slots 58 i which extends substantially tangentially tothe surface of the receptacle. As a result of this tangentialarrangement, a needle entering the receptacle 52 i will be directedtoward the fitting contained therein, but will generally not be able toenter and advance within the tangential slot 58 i so as to becomeentangled with the suture. As illustrated in this embodiment, the slotsmay optionally extend laterally through the foot so that the loop ofsuture can be pulled from one side of the shaft without interference.

A still further alternative mechanism for avoiding entanglement betweenthe suture and the needle is illustrated in FIGS. 10C and D. Two-partneedle 38 i includes an outer sheath 66 and an inner core 68. The partsof these needles initially advance together into the receptacles withthe needle core 68 withdrawn so that the needle presents a smoothtapered tip (the combined tip preferably being larger in diameter thanthe slot containing the suture) as illustrated in FIG. 10C. Oncetwo-part needle 38 i is fully positioned within the needle receptacle,needle core 68 may extend axially to expose barbed tip 42 and recessedengagement surface 44 and to secure the needle to the fitting within theneedle receptacle. In the exemplary embodiment of FIGS. 4 and 5, barbedtip 42 is formed integrally with the rest of the needle structure, butthe tip has a larger cross-section than radial slot 58 containing thesuture 34. As a result, the barbed tip is unable to enter the slot,thereby avoid entanglement between the needle and suture.

An alternative vessel closure probe 70 will be explained with referenceto FIGS. 11A through 11E. This embodiment includes an articulatable foot24 having a pair of needle receptacles 52, as described above. Althougheach needle receptacle 52 contains a fitting 40 for coupling a flexiblefilament to a tip of an associated needle, the filament in this casecomprises a short length of suture 74 (or some temporary connectingfilament, as shown schematically in phantom in FIG. 11A) spanningdirectly between the needle receptacles. Rather than pulling the twoends of an extended loop through the needle paths and proximally out thetissue tract for tying, closure system 70 advances a single end of thesuture distally along one needle path, across the puncture, and thenproximally along the other needle path. To provide this interaction, atleast one needle includes means for attaching suture 34 to short suture74, here in the form of a detachable coupling structure carried on theat least one needle. This structure facilitates the use of a pre-tiedknot.

Referring now to FIGS. 11A and B, the distal end of probe 70 advancesdistally through skin S and into a tissue T of the patient while theprobe is in the small profile configuration with foot 24 aligned alongthe axis of the probe. Here, however, an end 76 of suture 34 is affixedto a detachable needle tip 78 of a hollow needle 38′. Detachable tip 78comprises a fitting having an opening receiving an end of suture similarto fitting 40, attached to a barbed needle end (similar to that ofneedle 38). Suture 34 may extend proximally within hollow needle 38where the needle has an open channel along its length, may exit thehollow needle just proximally of detachable tip 78, or may be disposedalongside a solid needle. Needle 38 (opposite hollow needle 38′) has afixed barbed tip, as described above, and a bight of suture 80 isreleasably attached to the probe shaft encircling the opening of needleguide 54 of the fixed tip needle. The bight of suture may be releasablydisposed within a slot of the probe, may be temporarily held in place bya weak adhesive or coating, or the like. A second end 82 of suture 34extends proximally along the shaft of the probe, the second end of thesuture optionally also being releasably held along the shaft.

Bight 80 will define a knot when first end suture passes therethrough,as can be understood with reference to FIGS. 11A i and 11Aii. Bight 80will often include more than one loop, and may be pre-arranged so as todefine a square knot (using the layout schematically illustrated in FIG.11A i), a clinch knot (FIG. 11A ii), or a variety of known or newsurgical knots.

Probe 70 advances along tissue tract TT to puncture P in blood vessel V.Once foot 24 is disposed within a blood vessel V, a pull wire moves thefoot proximally and pivots the foot laterally so that the foot extendsalong an axis A of the vessel, as illustrated in FIG. 11B. The foot canthen be pulled proximally against an inner surface of the vessel wall Wto ensure that the needle receptacles 52 are properly positioned.

As can be understood with reference to FIGS. 11C and D, hollow needle38′ and needle 38 advance to engage fittings 40 within receptacles 52.Hollow needle 38′ draws first end 76 of suture 34 distally throughvessel wall W, and detachable tip 78 is secured into an associatedfitting 40 using the barb and tab interaction described above. As shortsuture 74 extends between fittings 40, and as detachable tip 78 can pullfree of hollow needle 38′ when the needles are withdrawn, thiseffectively couples needle 38 to first end 76 of suture 34. Thedetachable tip riding partially within the hollow needle (or vice versa)so that the assembly remains together under compression. Hence, needle38 can pull the suture distally along the needle path formed by hollowneedle 38′, across the puncture P, and proximally along the needle pathformed by needle 38, as illustrated in FIG. 11D.

FIGS. 11D and E show that the knot can be completed by pulling needle38, short suture 74, and second end 76 of suture 34 (together with thefittings 40 and detachable needle tip 78) proximally through bight 80.Second end 82 of suture 34 can be pulled to free bight 80, and the endsof the suture can be tightened and the probe removed to providepermanent hemostasis.

It will be recognized that removal of probe 70 can be facilitated bycoupling first end 76 to bight 80 over an outer surface of the probe,and by arranging suture 34 and hollow needle 38′ so that the suture canpull free of the needle when detachable tip 78 is released, for example,by having the suture exit the needle proximally of the tip through achannel that extends to the tip so that the needle does not encircle thesuture. By including such provisions, after foot 24 is returned to thenarrow configuration, the probe can be pulled proximally from the tissuetract leaving the pre-tied knot in place.

Alternative arrangements (using the detachable needle ends of probe 70)are possible to provide the benefit of a pre-tied knot and the like forclosure of a vessel puncture. For example, a probe having a pair ofneedles in which each needle included a detachable tip might be used topull first end 76 through a bight, so that the bight need not encirclethe needle path of one of the needles.

In some cases, particularly for closure of large punctures, it may beadvantageous to provide multiple suture loops across the puncture,either in parallel, in an “X” pattern, or the like. As illustrated inFIGS. 12A and B, the present invention encompasses the use of more thantwo needles and associated receptacles, fittings, sutures, and the like.Multiple loop systems may have four, six, eight, or more needles, or mayeven have odd numbers of needles and fittings, particularly where one ormore fittings have a plurality of suture ends extending therefrom. Thisallows a wide variety of stitching patterns to be provided by suchmultiple loop probes.

The method of use of the probes of FIGS. 1-7 can be understood withreference to FIGS. 13A-G. After accessing a blood vessel V (often usingthe Seldinger technique), a guidewire GW is left extending into skin Sand down through tissue T along tissue tract TT. Guidewire GW entersvessel V through a puncture P in vessel wall W, and extends along thevessel throughout many endovascular procedures. As illustrated in FIG.13A, distal guidebody 22 is advanced over the guidewire GW in a monorailfashion, so that the guidewire helps to direct the probe along thetissue tract TT and into the vessel through puncture P. FIG. 13B showsthat when sensor 36 is disposed within the vessel, blood can flow fromthe sensor port and through a lumen in shaft 12 to the proximal handleto notify the operator that foot 24 has been advanced far enough fordeployment.

Deployment of the foot is effected by actuation of the foot deploymenthandle, as described and illustrated above with reference to FIGS. 2 and2B. As described above, guidebody 22 helps to align the probe with theaxis of vessel V. Guidebody 22 may be set at an angle and/or offsetrelative to shaft 12 as appropriate to aid in alignment with aparticular vessel access technique. As shown in FIG. 13C, the deployedfoot 24 extends laterally from the shaft, so that foot 24 adjacentreceptacles 52 can be drawn up against vessel wall W by gently pullingshaft 12. Hence, the foot helps to accurately position the needle guides54 at a distance from the vessel wall.

Referring now to FIG. 13D, flexible needles 38 are deflected laterallyby needle guides 54 toward receptacles 52 of the deployed foot. As aresult, the needles advance in cantilever both distally and laterallywhen needle actuation handle 20 is pressed (see FIG. 2C), and thetapering surfaces of receptacles 52 help to push the needles back intoalignment with the fittings so as to overcome any unintended deflectionof the needles by tissue T or vessel wall W. This ensures that needles38 securingly engage fittings 40 within receptacles 52, thereby couplingthe ends of suture 34 to the needles. While suture 34 is hereillustrated running along the side of shaft 12 outside foot receptacle30 to a lumen within guidebody 22, it should be understood that thesuture loop might instead extend proximally in a lumen of shaft 12,might be routed through the foot and/or foot receptacle, and/or might bestored in a spool adjacent foot 24. Regardless, suture 34 should able topull free of the probe between its ends to form a continuous loop acrosspuncture P.

Referring now to FIGS. 13E and F, fittings 40 and the ends of suture 34are drawn proximally through the vessel wall W along the needle pathsformed by needles 38. Optionally, the needles may be withdrawnproximally out of the tissue tract and clear of shaft 12, or they mayremain coupled to the shaft within needle guides 54. The foot actuatoris moved to store foot 24 along shaft 12, and the shaft can then bepulled proximally from the tissue tract. Guidebody 22, which maycomprise a soft, compliant polymer, may temporarily extend at leastpartially into tissue tract TT and through puncture P to help reduce theloss of blood until the loop is secured.

Now referring to FIG. 13G, once shaft 12 has been withdrawn sufficientlyto expose needle guides 54, the ends of the suture loop can be graspedby the operator. Tying of a knot in suture 34 can then proceed in aconventional manner. The use of a clinch knot may facilitate gradualtightening of the knot while removing guidebody 22, although a widevariety of knot and knot advancing techniques might be used.

While the exemplary embodiments have been described in some detail forclarity of understanding, a wide variety of modifications, adaptations,and changes will be obvious to those of skill in the art. For example,some of the benefits of the present invention might be provided byactuating a foot disposed outside the blood vessel within the tissuetract, and advancing needles from within the blood vessel proximallythrough the vessel wall toward the actuated foot. Hence, the scope ofthe present invention is limited solely by the appended claims.

1-37. (canceled)
 38. A system for suturing a blood vessel, the vesselhaving a vessel wall, the system comprising; a first needle having aproximal end and a distal end suitable for forming a first needle paththrough the vessel wall; a flexible filament; and a first fittingattached to the filament, the first fitting securingly engaging thefirst needle when the first needle advances through the vessel wall sothat the first fitting and at least a portion of the filament can bewithdrawn proximally along the first needle path by the first needle.39. The system of claim 38, further comprising: a shaft having aproximal handle and a distal end suitable for insertion into the vesselthrough the first needle path; and a foot mounted near the distal end ofthe shaft, the foot having a first needle receptacle and articulatablefrom a small profile configuration to a large profile configuration byactuation of the handle, wherein the first fitting is removably mountedadjacent the first needle receptacle, and wherein the first needle isadvanceable from the shaft to the first needle receptacle on thearticulated foot.
 40. The system of claim 39, wherein the filamentcomprises a first suture and couples the first fitting to a secondfitting.
 41. The system of claim 40, further comprising a second needlereceptacle disposed near the distal end of the shaft and a second needleadvanceable from the shaft to the second needle receptacle to withdrawthe second fitting proximally through the vessel wall and form a sutureloop across the puncture.
 42. The system of claim 41, wherein the secondfitting is coupled to the filament and disposed within the second needlereceptacle.
 43. The system of claim 42, wherein the second needle isadapted to form a second needle path through the vessel wall and havinga second suture releasably mounted thereon, wherein the second fittingcouples the filament to the second suture so that the second suture canbe withdrawn proximally along the first needle path through the vesselwall formed by the first needle to form a suture loop across thepuncture.
 44. The system of claim 43, wherein the second fitting has anopening and at least one tab that extends into the opening, wherein thetab securely engages the engagement surface of the second needle whenthe second needle advances through the vessel wall and into the opening.45. The system of claim 38, wherein the first needle comprises arecessed engagement surface adjacent the distal end, and the firstfitting comprises an opening and at least one tab extending into theopening, the tab securingly engaging the engagement surface when thefirst needle advances through the vessel wall and into the opening sothat the first fitting and at least a portion of the filament can bewithdrawn proximally along the first needle path by the first needle.46. The system of claim 38, further comprising: a shaft having aproximal end and a distal end and defining an axis therebetween, theshaft having a size and configuration suitable for insertion through theopening in the tissue; a foot mounted near the distal end of the shaft,the foot being articulatable from a low profile configuration to adeployed configuration extending laterally from the shaft; and anactuator extending along the shaft distally to the foot, movement of theactuator sliding the foot axially and pivoting the foot from the lowprofile configuration aligned along the shaft to the deployedconfiguration extending laterally from the shaft.
 47. The system ofclaim 46, further comprising: a suture supported by the foot; and aneedle advanceable from the shaft through the tissue and to the deployedfoot.
 48. The system of claim 47, wherein the foot includes a firstneedle receptacle.
 49. The system of claim 38, wherein the at least onetab resiliently deflects into an indentation adjacent the engagementsurface when the first needle advances into the opening.
 50. The systemof claim 38, wherein the first fitting comprises a tube having aproximal end and a distal end, the opening extending into the proximalend, the at least one tab formed of tube material by cutting slotsthrough the tube, wherein the filament extends distally from the distalend of the tube.
 51. The system of claim 50, wherein the first fittingfurther comprises a collar disposed about the filament, the collarcrimped over an end of the filament.
 52. The system of claim 38, whereinthe first needle is flexible, and wherein the first fitting isreleasably supported within a receptacle surface oriented to laterallydeflect the advancing first needle toward the first fitting.
 53. Thesystem of claim 52, wherein each receptacle surface tapers from a smallcross-section adjacent the first fitting to a large cross-sectionoriented toward the advancing first needle.
 54. The system of claim 52,further comprising a slot disposed along the receptacle surface, whereinthe filament is releasably disposed in the slot, the slot configured toavoid engagement of the first needle with the flexible filament.